Laserfiche WebLink
<br />north of the town of Green River, Utah. The complex consists of a raceway, Thayn power plant <br />and pump station, Thayn Ditch, and the Green River Canal (Figure 1; Cavalli 2000). The <br />diversion dam is 840 feet long (256 m), stands 8 feet high (2.4 m), and is constructed of rock and <br />timber crib with a concrete overlay (Thayn and Thayn 1983; Cavalli 2000). The dam was <br />assembled in 1906 to divert the flow of the Green River into the raceway and canal on the west <br />side for agricultural and hydropower usage (Colorado River Fish Project 1984; Cavalli 2000). <br />Water is generally diverted to the Green River Canal and the Thayn Ditch in April and drained in <br />November. Whereas, the raceway and power plant have water year round. The Tusher Wash <br />complex requires approximately 715 ft3/s (20.25 m3/s) for full operation (Cavalli 2000). Water <br />is distributed to the Thayn power plant and pump station, Thayn Ditch, and Green River Canal. <br />The canal is approximately 8.14 miles long (13.10 km) and reconnects to the Green River north <br />of Interstate 70. Eighty ft3/s (2.26 m3/s) of water passes into the canal during the irrigation <br />season (Cavalli 2000). <br />METHODS <br />Larval Sampling in the raceway and Green River Canal <br />Larval traps and drift nets were fished on 14 June 2000 in the raceway and Green River Canal. <br />Six light traps were set above the Thayn Power plant and pump station in areas with zero or <br />minimal current in the raceway. The traps were fished 1652-h to 0515-h, approximately 13 <br />hours. The catch was placed into glass jars and preserved in 10% formaldehyde. <br />Two larval drift nets (1/16" X 1/32" mesh, 22" X 4" catch tube, 19"X13" mouth, 11.5 feet long) <br />were set in the Green River Canal between the Thayn Power Plant and first siphon (Figure 2). <br />The nets remained in the canal from two to six hours. All six samples collected had large